Pneumatic gun



(No Model.) 3 Sheets- Sheet 1.

N. W. PRATT. PNBUMATIG GUN.

No. 430,087. Patented June l0, 1890 ATTORNEY me mams Penas au., mom-mno., msnmamu, u. c.

(No Model.) 3 Sheets-Sheet 2.

N. W. PRATT. l l PNEUMATIG GUN. No. 430,087. y Patented June 10, 1890.

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(No Model.) 3 Sheets-Sheet 3.

N. W. PRATT.

PNBUMATIG GUN.

No. 430,087.- Patented June- 10, 1890.

ENTUB @v4/fb ATTORNEY nnnnnn ms Pneus ce., momumo., wAsv-nnuwu, n, c:y

UNITED STATES PATENT OFFICE.

NAT. 1V. PRATT, OF bROOKLYN, NEV YORK.

PNEUMATIC GUN.

SPECIFICATION forming part of Letters Patent No. 430,087, dated June 10, 1890.

Application filed March 19, 1887.

Serial No. 231,601. (No model.) Patented in England .Tune 28, 1887, No. 9,198; in France .Tune 28, 1887, No. 184,509; in Belgium ,Tune 28,1887,No.77,786; in Germany June 28,1887,No.42,751; in Norway .Tune 28, 1887, No. 579; in Sweden .Tune 28, 1887, No. 1,619; in Italy June 30, 1887, Nos. 21,957 and 304; in Spain August 10, 1887, No. 11,218; in Chili November 2, 1387; iu Brazil November 5, 1887, No. 533, and in Austria-Hungary December 8,

1887, No. 25,766 and No. 56,723.

To all whom it may concern:

Be it known that I, NAT. W. PRATT, a vcitizen of the United States, residing at Brooklyn, county of Kings, and State of New York, have invented certain new and useful 1mprovements in Pneumatic Guns, of which the following is a specification, reference being had to the accompanying drawings.

This application was patented J une 28, 1887,i11 the following countries: in England, No. 9,198; in France, No. 184,509; in Belgium, No. 77,786; in Germany, No. 42,751; in Norway, No. 579; in Sweden, No. 1,619; in Italy June 30, 1887, No. 21,957 and No. 304; in Spain August 10, 1887, No. 11,218; in Chili November 2, 1887, no number; in Brazil November 5, 1887, No. 533; in Austria-Hungary December 8, 1887, Nos. 25,766 and 56,723.

This invention relates to ordnance in which projectiles are discharged from a gun by compressed-air or other compressible fluid agent, the purpose being to avoid the concussion incident to the discharge by an explosive agent, and whereby the employment of a shell containing a highly-explosive charge is rendered practicable.

The object of the invention is to provide means for quickly restoring and maintaining the normal tiring-pressure in the firing-reservoir, to so locate the movable jointed connection of the firing-port as to relieve the same from pressure except during the act of tiring, and to acquire an accurate control over the range of the projectile by a predetermined pressure-charge.

The invention consists in universally jointing the iiring-port connection (as by a balland-socket joint) proximate to the point of connection to the gun-barrel,whereby anniversal training movement of said barrel horizontally, vertically, or ,obliquely is permitted, and the iiring-valve located at a point between the pressure source and the said connection for the purpose of relieving the same from pressure when the tiring-valve is closed.

The invention further consists of an autotomatic firing-valve and valve-operating device, whereby thc action of said valve is regulated to deliver the compressed iiuid in predetermined quantities, said quantities being variable at will, for the purpose of controlling the range of the projectile, irrespective of the control of the operator during the act of tiring.

In order that others skilled in the art to which my invention appertains may be enabled to understand and practice the same, 1 will proceed to describe the features of its construction in detail, explain its operation, and point out in the appended claims the essential features which I claim as new.

I have shown in the accompanying drawings a movable-gun system embodying one form of structure by which the various features of my invention may be carried into practice; but it is obvious that the doublereservoir system and iiring-valve mechanism herein shown are equally applicable to a fixed-gun system-z'. e., one having the barrel placed at a permanent angle of elevation.

Referring to the drawings, in which like tigures of reference represent like parts throughout the several views, Figure 1 is a side elevation of a pneumatic gun; Fig. 2, a plan view of Fig. 1; Fig. 3, an enlarged vertical central section of the rear-portion of the same; Fig. 4, a plan view of the lower portion of Fig. 3-naniely, the revolving truck, the foundation, and the ball of the ball-and-socket pipejoint; Fig. 5, an enlarged vertical section of the firing-valve and valve-operating mechanism; and Figs. 6 to 10, inclusive, detail views of the said operating mechanism.

1, Fig. 1, is an elongated barrel composed of sections bolted together by flanges 2 and mounted upon a truss-frame 3, being secured thereon by means of straps 4, and a casting 5 composing the breech of the barrel. The whole is capable of swinging vertically upon thel trunnions 6, which are supported in pillow-blocks 7 of a revolving truck 8.

The truck 8 rests upon truck wheels 9, which travel on the circular track 10 of the lfoundation 11 during the horizontal training movement of the gun. The truck 8 has a forwardly-projecting frame or carriage 12, provided with a forward truck 13, moving on a track 14, and which supports the weight 36, Figs. 1 and 3.

of the gun by agency of the hydraulic cylinder 15 and plunger 16, pivoted respectively at 17 and 18 to the frame of said carriage and the frame of the gun-barrel.

The casting 19, fixed to the foundation, isA

provided with a grooved rim 20 for the reception of a cable 21, secured thereto. The extensions of the cable 21 are passed over sheaves 22 upon the truck-frame S, and thence are held taut by pistons in the hydraulic cylinders 23, the latter being secured to the carriage 12. The piston-rods 24 extend partly through the sleeves 25, fastened to the carriage, and are coupled at points 26 to the ends of the cable, the said sleeves being for the purpose merely of protecting the parts. The gun is by this construction capable of vertical or horizontal training movements, or both simultaneously, according to the directed flow of water conveyed through pipes to the several hydraulic cylinders.

The breech of the gun is lprovided with a hinged valve 27, Fig. 3, for the introduction through the opening 28 of the projectile. The hinged valve may be provided with a suitable returnin g-sprin g to assist in throwingit home to its seat preparatory to applying the firingpressure.

The movable ball-and-socket pipe-joint 29, Fig. 3,is located in line with the trunnions 6, and in the vertical axis of the revolvingtruck 8, acting as a pivot therefor and permits the universal movementrequired for the training of the gun. The socket is made separable, as shown, having central flanged divisions bolted together in the usual manner of similar joints. The ball part 30 is secured to or forms a part of the casting 19, and to the flange 31 of said castingis secured the casing 32 of the firing-valve, to which the reservoirpipe is bolted. The conical casting 19 forms a support or brace for the joint and a protecting-shield for the valve and connections below said casting.

The opening into the breech of the gun just above the hollow joint 30 is enlarged or ared, so that whatever the position of the gun with respect to said joint said opening will always be in full communication with the opening in the joint.

The magazine-reservoir 33 (shown by dotted lines, Fig. 1) and firing-reservoir 34 are preferably placed beneath the ground, the latterl reservoir being connected tothe firingvalve by the pipe 35, having a throttle-valve The magazine and firing reservoirs are capable of communication through the tube 37, carried for convenience to the interior of the foundation and controlled by a cock 3S.

The firing-valve consists of a plunger 39, Fig. 5, having different areas presented byits opposite ends, the greater being exposed to the chamber 40, in which the flange 41 of said valve acts as a piston, the space 42 back of said flange being open to the atmosphere. The diameter of the valve end of the plunger is slightly in excess of the exterior margin of the valve-seat 43, which feature causes the valve to start from its seat the instant pressure in the chamber' 40 falls sufi'icientlyhelow that within the pipe 35. The top of the valve is weighted by a tapering head, which by its form causes a comparatively gradual discharge of pressure at the initial descent of the valve, and avoid, a blow to the projectiles which would result by overcoming its inertia with an abrupt shock of pressure to the intervening space between the said valve and said projectile. The gradual discharge aforesaid iirst charges the intervening space with a pressure-cushion and starts the projectile before the impelling body of fluid acts with full force thereon. The chamber40 is charged and exhausted through the port 45.

The automatic valve-operating mechanism (represented by Figs. 5 to 10, inclusive) consists of a piston exhaust-valve 46, having a cup-shaped end fitting the seat` 47 of the exhaust-passage 48, and also sliding air-tight in .the cylindrical chamber 49, so as to control the induction-pipe 50, which latter is connected, as shown in Fig. 3,to the main reservoir-pipe.

The stem 51 of the exhaust-valve 46 extends air-tight through the fixed bushing or diaphragm 52, held in place between the sections 53 and 32 of the valve-easing, and upon the end of said stem is secured the operating-piston 54, sliding air-tight in the Vcylindrical chamber 55. The piston 54 is of greater diameter than thepiston-valve 46, and the chamber 55 communicates through the port 56, located in front of the piston 54, with the port 5S of the cut-off valve 59, Figs. 7 and 8, the cavity 57 being connected to the port 58. The portion of the chamber 55 back of the piston 54 acts as an air-cushion for returning the valve when it is forced out. Pressure conveyed through the pipe 60 from the main Areservoir-pipe, Fig. 3, to the back of the cutoif valve 59 is alternately charged to the chamber 55 and exhausted therefrom through the exhaust-pipe 61 by the rocking movement of the said valve, the same being actuated by means of its arms 64 65, bythe latch 62, Figs. 5, 6, and 9, when moved to the position shown by Fig. 7, and returned to the position shown by Fig. 8 by the stem 63 of the piston 54. I do not, however, confine myself to the cut-oli"- valve construction shown in the accompanying drawings as means of charging the chamber 55 and exhausting the pressure therefrom. The said valve may be constructed having a charging function only, dispensing with its exhausting function, and may be operated with a positive connection, directly or indirectly, to the hand-lever 66, and an independent valve of any suitable construction may be employed, to be released when the latch is tripped, for the purpose of exhausting said chamber 55.

The latch 62 is operated by the hand-lever 66, so that hv the downward movement of said lever, as in Fig. 6, the enlargement of the IOL slot'67, Fig. 9, is brought into line with the stem-shoulders 68 of the stem 63, Fig. 10, permitting the pressure in the chamber to throw said stem out, shifting the valve 59 to its exhausting position, whereupon the piston 54 and stem 63 are returned by the pressure from the pipe 50 on the back of the valve 46, and by aid of the air-cushion aforesaid and the latch 62 reset by the upward movement of the hand-lever. i

In order to insure the accuracy ot the predetermined ring-charge, it will be observed that the latch 62 trips the piston 54 while the same is under pressure by an instantaneous movement, irrespective ot' the speed with which the gunner handles the firing-lever 66.

The exhaust-pipe 6l is provided with a controlling escape valve or cock 69 of any suitable construction, havin g a handle and graduated indicating-disk by which it may be set to predetermine the period of the exhausting` action herein described, which in turn regulates the action of the tiring-valve.

yIn order to avoid an unnecessarily line adjustment of parts in the construction of the escape-valve 6l, the volume of fluid which must be exhausted through the same is increased by means of the chamber-enlargement 57 of the chamber 55, so that a proportionate enlargement of the valve-openin g, and consequently greater movement, is acquired, decreasing the effects of a possible variation in the operating adjustment.

The magazine-reservoir being charged from a suitable source (as a compressor) with a pressure exceeding that of the desired tiringpressure --say two thousand pounds per square inch, and the" firing-reservoir being charged with a tiringpressure-say of one thousand pounds per square inch, the operation of my invention is as follows: The pressure is charged through the pipe 35 both to the annular space 70 about the firing-valve and to the chamber 40 through the tube 50 and port 45. The tiring-valve is thereby held against its seat by the greater pressure area of its lower side. The pressure is also admitted through the pipe to the back of the valve 59. The gun is elevated to the required angle with regard to the desired limits of range and with consideration of the degree ot firing-pressure at command. The projectile having been introduced into the barrel through the breech-opening 28 and the valve 27 closed, the gun is ready for action. The action of the tiring-valve mechanism may be considered as divided into four separate acts: first, latching the exhaust valve 46 in its closed position by an upward movement of the hand-lever 66 and subsequently charging the pressure side of the exhaust-valve piston 54 by a continued upward movement of said lever to the position of Fig. 5 preparatory to iirin g second, the firing movement-namely, the depression of the lever 66 tripping the latch 62, the pressure on the greater piston area 54 driving the exhaust-valve 46 open;

third, the dwell open, due to the retarding action of the controlling escape-valve 69 upon the exhaust of theindependentsystem of pressure on the piston 54, and, fourth, the return of the exhaust-valve 46 to its seat, due to constant pressure back of the said valve from the pipe 50. The action thus described of the exhaust-valve 46 exercises a corresponding con-` trol over the action of the tiring-valve 39, the movement of which is divided into three separate acts: lirst, aninstantaneous wide-open motion; second, a variable dwell in this position, and, third, an instant closure. It will therefore be understood that the variable dwell aforesaid is subject to the positive control of the adjustable escape-valve 69, and that the personal equation of the gunner-that is to say, his control over the volume discharged during the act of firing-is eliminated by this construction, the range of the gun (for a given angle of elevation) being variable by a predetermined independent adjustment of the said escape-valve, rendering the subsequent action automatic.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

l. The combination, in a pneumatic gun, 0f an automatic firing-valve, au actuating pressure chamber for said valve, an exhaustvalve controlling the induction and eduction of pressure to and from said chamber, a piston connected with said valve and moving in a cylinder, a cut-off:` valve for controlling the admission of fluid to actuate said piston, a latch device for tripping the said piston, and an adjustable escape-valve for controlling the exhaust from the cutoit valve, substantially as described.

2. The combination, ina pneumatic gun, of a liring-valve, an actuating pressure-chamber therefor, an exhaust-valve for controlling the induction and eduction to and from said chamber, a piston connected to said valve and moving in a cylinder, a cut-ott' valve for controlling the admission of fluid to and from one side of said piston, a hand-operated latch for holding the piston in one position against the pressure of i'luid entering its cylinder, and a cut-off valve actuated in one direction by the movement of the piston for exhausting the fluid from its cylinder and allowing the piston and exhaust-valve to return to their normal position, substantially as described.

3. The combination, in a pneumatic gun, of a ring-valve, an actuating pressu re-chamber for said valve, an exhaust-valve for controlling the induction and eduction of fluid to and from said chamber, a piston on the stem of said valve and moving in a cylinder, a cutoff valve for controlling the admission of iluid to and from one side of said piston, a hand-operated latch for holding the piston in one position against the pressure of the fluid in its cylinder and operating said valve in one direction, and an adjustable escape-valve for regulating the size of the exhaust-opening IOO IIO

from the cut-off valve, substantially as described.

A 4. In a pneumatic-gun system, the combination of a gun-barrel capable of both vertical and horizontal movement about a iiXed center, a stationary pressuresreservoir, a reservoir-pipe connection forming said center of movement and capable of yielding to the barrel movement aforesaid, and a firing-valve, said firing-valve being interposed between the said yielding connection and the reservoir, for the purpose set forth.

5. The universal joint, the conical casing connected to said joint and forming a brace therefor, the gun supported on said joint, and the supply-pipe leading to said joint from below the conical casin g, in combination, substantially as described.

6. The universal joint and the gun supported thereon, the supply-tube leading to a passage through said joint, a valve in said supply-pipe, and the conical shield connected to one of the members forming the joint, acting as a brace thereto, and covering and shielding the valve and supply-pipe, all combined substantially as described.

7. The combination, With the gun, the conical shield, and tho foundation, of a Iii-ingreservoir having a supply-pipe leading under the conical shield and up to the gun, as described, and a magazine-reservoir having a supplypipe leading under the shield and thence to the firing-reservoir, substantially as described.

8. In a gun-firing valve, the reciprocating main piston having unequal pressure areas, a controlling-valve governing the escape from the main Valve, a relief-valve governing an inlet and escape passage to the controllingvalve, and operative mechanism between the relief and controlling valves by which the controlling-valve is locked or unlocked, in combination, substantially as described.

9. In a pneumatic-gun valve, the main iiring-valve piston having vunequal pressure areas, a separate valve controlling au outlet from one of the main pistoirchambers, and a piston connected to said controlling-valve and working in a cylinder to actuate said valve, and means for controlling pressure in said cylinder, in combination, substantially as described.

10. In a pneumatic gun, a main iiring-valve having a piston with unequal pressure areas, substantially as described, and a tapering projection extending forward into the path of movement of the gas Which passes the valve to reduce the area of said opening when the valve first starts, and a separate valve controlling the movement of said piston, in combination, substantially as described.

NAT. W. PRATT.

Witnesses:

CHAs. W. FORBES, ELMER A. ALLEN. 

